Inspired by having just read a bad first novel by an author whose previous published work a collection of short stories was extremely good, widely acclaimed and multi-prize-winning.
It's not so much that I'm disappointed as that I'm completely baffled as to how an experienced writer who wrote a psychologically acute and dazzlingly well-written collection of stories, which entirely deserved their praise and prizes, could have gone on to write such a banal novel, which commits every possible beginner writers' mistake clichéd adultery plot, far too many characters who aren't differentiated from one another, an antagonist whose age varies, barely sketched-in settings, lots of small errors like variations in how long ago something major happened and how far apart places are and an unintegrated subplot about a dead friend and a past friendship group none of whom are ever described other than in brief asides, so it's hard to care about them at all other than wonder what they're doing in the novel.
(And this came out with a major publishing house, so how come her editor didn't clock lots of the small inconsistencies, even if the author got confused?)
Anyway -- it got me thinking about other writers whose previous work I've loved but then been disappointed by when they brought something new out. The other example I can think of is Hilary Mantel's The Assassination of Margaret Thatcher, which I felt was a loop back to the repellent nastiness of her earliest published novels, and away from the wonderful first two Cromwell novels.
Anyone else?